In recent years, oil and gas well exploration have ventured into increasingly deeper waters. As a result, we now have pipeline laid at depths far exceeding the limits at which divers can safely and/or easily work. Consequently, in response to the needs of the industry, new generations of equipment and methods to lay and maintain pipeline have been developed.
In particular, equipment and methods have been developed to repair breaks or "wet buckles" which may occur in the pipeline at deep water depths. Typically, either a totally remote, unmanned repair apparatus or an apparatus which includes a submersible diving bell has been used for this purpose.
These methods and apparatus have not proven totally satisfactory from either a cost or efficiency viewpoint. In particular, these earlier methods and apparatus have not provided the flexibility, maneuverability, and ease of handling which the cost conscious offshore petroleum industry must have.
It is therefore an object of this invention to provide improved methods and apparatus for repairing a break or wet buckle in an elongated pipeline lying in deep water. Another object of the invention is to provide methods and apparatus for repairing a break or wet buckle which occurs while the pipeline is being laid.
Other objects of the invention include providing a method and apparatus which does not require diver assistance, which is reliable, which accomplishes the manipulations required to effect pipeline repair both efficiently and precisely, which enjoys a large degree of flexibility and maneuverability, and which is easy to control from a submersible vehicle.